Exponential gravity with logarithmic corrections in the presence of axion dark matter

TL;DR

This paper explores an exponential modified gravity model with logarithmic corrections incorporating axion-like scalar fields as dark matter, comparing its observational fit to the standard $\\Lambda$CDM model.

Contribution

It introduces a novel gravity model with logarithmic corrections and assesses its viability as a dark matter candidate using observational data.

Findings

Model fits observational data similarly to $\\Lambda$CDM.

Number of free parameters favors $\\Lambda$CDM.

Results are not statistically significant to rule out models.

Abstract

An exponential modified gravity with additional logarithmic corrections is considered with the presence of an axion-like scalar field in the role of dark matter. Axion fields are thought to become important at late-times when the axion-like scalar field oscillates around its vacuum expectation value, mimicking dark matter behaviour. The model is compared with the usual pressureless fluid description of dark matter. Both models are tested with observational data including some of the latest sources, providing similar fits in comparison with the $\Lambda$CDM model. Despite results are not statistically relevant to rule out any model, the number of free parameters still favours $\Lambda$CDM model, as shown by computing the goodness of the fits.